JP6769645B1 - Vaporizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vaporizer capable of satisfying a required flow rate of a liquid raw material to be vaporized without a decrease in heat transfer efficiency not only in a small flow rate but also in a large flow rate. SOLUTION: A vaporizer A is housed in a hollow outer tube 1 and an outer tube 1 connected to a base 7k of an atomizer 7 and an atomizer 7 in which a spray port 73 is formed, which atomizes and blows out a liquid raw material L. The inner heater block 8 provided inside the inner tube 2 and the inner tube 2 made of quartz glass or heat-resistant glass and incorporating the inner heater 9 is included. The outer tube 1 and the inner tube 2 are made of quartz glass or heat-resistant glass. An inner filling layer 10 filled with graphite powder is formed between the inner peripheral surface of the inner tube 2 and the outer peripheral surface of the inner heater block 8. [Selection diagram] Fig. 1

Description

The present invention relates to a vaporizer having excellent vaporization efficiency, which is particularly suitable for semiconductor manufacturing and optical waveguide formation.

There are wet oxidation and dry oxidation as types of thermal oxidation methods for semiconductor materials such as Si and SiC. Water is used for wet oxidation. H ₂ O is passed into the furnace as gas (water vapor) and oxygen in water is used for the growth of the oxide film. The characteristic of wet oxidation is that the oxidation rate is high. Therefore, this method is used when a thick film thickness is required. On the other hand, dry oxidation uses oxygen gas for oxide film growth. This is the opposite of wet oxidation, and the growth rate of the oxide film is slow. In recent years, hydrogen peroxide (H ₂ O ₂ ) has come to be used instead of water (H ₂ O) in order to further increase the growth rate of the oxide film. On the other hand, applications other than semiconductors include the formation of optical waveguides. (See Patent Document 1). In this case, the deposition thickness of the silicon dioxide 10 to 25 [mu] m (SiO _2), the oxidation method using _{H 2} O, requires a long deposition time. By using hydrogen peroxide _(H 2 _{O 2)} in place of H ₂ O, it is possible to significant time savings.

For that purpose, it is necessary to vaporize a large amount of hydrogen peroxide solution and send it to the reactor. As an apparatus for such a purpose, an apparatus as shown in Patent Document 1 has been proposed.
The vaporizer described in Patent Document 1 that vaporizes a hydrogen peroxide solution to generate an oxidizing gas heats the lower half of the vaporizer of a hollow spherical container similar to a flask containing the hydrogen peroxide solution from the outside. The hollow spherical container is heated to 100 to 130 ° C., and the steam containing the vaporized hydrogen peroxide gas flows into the reactor through the gas supply pipe. This device simply heats and vaporizes the hydrogen peroxide solution, and as the hydrogen peroxide solution evaporates in the vaporizer, not only the concentration of hydrogen peroxide changes, but also the vaporization efficiency is poor. It is a drawback.

Therefore, a vaporizer having far superior vaporization efficiency as compared with the vaporizer described in Patent Document 1 has been proposed (Patent Document 2).
The vaporizer described in Patent Document 2 is housed in an atomizer that atomizes and blows out a liquid raw material, a hollow outer tube to which a spray port of the atomizer is connected, an outer tube, and a spray outlet of the atomizer and its spray port. An inner tube with an atomized space formed between it and the tip, an outer heater block provided outside the outer tube and with a built-in outer heater, and an inner heater provided inside the inner tube with a built-in inner heater. It is composed of an inner heater block. Then, for vaporization, the vaporized gas that is heated and gasified while communicating with the atomized space between the inner peripheral surface of the outer tube and the outer surface of the inner tube and passing through this gap is sent to the next process. There is a gap.

In this vaporizer, the inner heater block is made of aluminum, and the inner tube containing the inner heater block is made of quartz glass. Since the coefficient of thermal expansion of the inner tube is almost zero, which is very small compared to the coefficient of thermal expansion of the aluminum inner heater block, the gap between the two is to prevent damage to the inner tube from the thermal expansion of the inner heater block during vaporization. I try to take a large size. However, if the gap between the two is large, the gap between the two becomes an air layer with high heat insulating properties, so that heat from the inner heater block is not easily transferred to the inner tube, and the vaporization performance is significantly impaired. .. Therefore, this gap is filled with heat transfer paste.

Japanese Unexamined Patent Publication No. 2001-337240 Japanese Patent No. 6203207

Recently, however, an increase in the flow rate of liquid raw materials has been required due to an increase in the amount of vaporized gas used. If the flow rate of the atomized fluid to be vaporized injected from the atomizer is increased according to the request, it is necessary to increase the amount of heat supplied, and therefore a higher temperature is required. Since the heat transfer paste is composed of a solid metal component and a solvent, its own thermal conductivity is low as described later, and when the temperature of the inner heater is set to a high temperature, it is a component of the heat transfer paste. The paste evaporates leaving only the solid components. In that case, the heat transfer efficiency is significantly reduced. As a result, there has been a problem that the vaporization performance is remarkably lowered and the target flow rate of the liquid raw material to be vaporized cannot be obtained.

The present invention has been made to solve such a problem, and an object thereof is to vaporize a required liquid raw material without a decrease in heat transfer efficiency not only in a small flow rate but also in a large flow rate. The purpose is to provide a vaporizer capable of satisfying the flow rate.

The present invention
Atomizer 7 that atomizes and blows out the liquid raw material L,
A hollow outer tube 1 of the atomizer 7 connected to a base 7k on which a spray port 73 is formed and made of quartz glass or heat-resistant glass, and
An inner tube 2 housed in the outer tube 1 and made of quartz glass or heat-resistant glass, and
A vaporizer A provided inside the inner tube 2 and including an inner heater block 8 having an inner heater 9 built therein.
The tip head 2a on the insertion side of the inner tube 2 is arranged so as to face the spray port 73, and is between the base 7k on which the spray port 73 is formed and the tip head 2a on the insertion side. Atomized space M is provided,
A vaporization gap 3 communicating with the atomization space M is provided between the inner peripheral surface of the outer tube 1 and the outer peripheral surface of the inner tube 2.
An inner filling layer 10 filled with graphite powder is formed between the inner peripheral surface of the inner tube 2 and the outer peripheral surface of the inner heater block 8.

In the present invention
An outer heater block 5 provided on the outside of the outer tube 1 and equipped with the outer heater 4 is further provided.
An outer filling layer 6 filled with graphite powder is formed between the outer peripheral surface of the outer tube 1 and the inner peripheral surface of the outer heater block 5.

The present invention is characterized in that the inner heater block 8 is formed of a graphite block.

In the vaporizer A according to the present invention, since the outer tube 1 and the inner tube 2 are made of quartz glass or heat-resistant glass, for example, hydrogen peroxide solution having high oxidizing or erosive properties, or other corrosive or erosive properties. It is possible to vaporize the high liquid raw material L.

Since the inner packing layer 10 of graphite powder is formed between the inner peripheral surface of the inner tube 2 and the outer peripheral surface of the inner heater block 8, even if the inner heater block 8 thermally expands during heating, this expansion occurs. The amount is absorbed by the inner filling layer 10 to prevent damage to the inner tube 2 made of quartz glass or heat-resistant glass.

Further, since the outer packing layer 6 of graphite powder is formed between the outer peripheral surface of the outer tube 1 and the inner peripheral surface of the outer heater block 5, even if the outer heater block 5 shrinks during cooling, this shrinkage amount. This can be absorbed by the outer packing layer 6 to prevent damage to the outer tube 1 made of quartz glass or heat-resistant glass.

Further, since the thermal conductivity of the inner packed layer 10 and the outer packed layer 6 filled with the graphite powder is superior to that of the conventional heat transfer paste, more heat from the heaters 4 and 9 is transferred to the vaporization gap 3. It is possible to suppress the amount of heat generated by the heaters 4 and 9.

It is a vertical sectional view of one Example of this invention. It is a cross-sectional view taken along the line ZZ of FIG. It is a Y partial enlarged view of FIG. It is an enlarged sectional view of the atomizer (X part) of FIG. It is a schematic flow chart of the whole system using the vaporizer of this invention.

Hereinafter, the present invention will be described with reference to the drawings. The vaporizer A is roughly composed of an atomizer 7, an outer tube 1, an inner tube 2, an outer heater 4, an outer heater block 5, an inner heater block 8, an inner heater 9, and a temperature sensor 12.
The liquid raw material L applied to the vaporizer A may be any liquid raw material L that is vaporized and used (for example, various liquid raw materials used for semiconductor manufacturing), but here, as a typical example thereof, hydrogen peroxide Use hydrogen peroxide water.
When the vaporizer A is for vaporizing hydrogen peroxide solution and requires extremely high purity hydrogen peroxide-containing steam G2 as in a semiconductor manufacturing apparatus, it is not attacked by hydrogen peroxide-containing steam G2 in a high temperature environment. The outer tube 1 and the inner tube 2 are made of such quartz glass.
Since the atomizer 7 also comes into contact with the hydrogen peroxide solution, it is preferably formed of quartz glass, but those having a complicated shape are formed of, for example, a tetrafluoroethylene resin.
Heat-resistant glass such as Pyrex (registered trademark) glass can also be used if the conditions for the liquid raw material L are met.

The atomizer 7 atomizes the liquid raw material L, and has a base portion 7k that is in airtight contact with one end of the outer tube 1, a spray gas pipe 7a projecting from the base portion 7k, and the spray gas pipe. It is composed of a liquid raw material introduction pipe 7b attached at an angle equal to or close to 7a (FIGS. 1 and 4). The atomizer 7 in the figure is abbreviated and described, and those having various structures are used.

As described above, the atomizer 7 is composed of a base portion 7k, a spray gas pipe 7a, and a liquid raw material introduction pipe 7b.
The base portion 7k has a disk shape, and one end of the outer tube 1 is in airtight contact with the outer tube 1.
The spray gas pipe 7a is projected from the center of the base portion 7k, and a main supply hole 7c through which the carrier gas G1 for vaporization passes is formed in the center thereof. The tip of the main supply hole 7c is narrowed in a conical shape, and a spray port 73 is provided.
A liquid raw material introduction pipe 7b is provided on the side surface of the spray gas pipe 7a, and the liquid raw material introduction pipe 7b is provided with a sub supply hole 7d communicating with the main supply hole 7c.

The outer tube 1 is a cylindrical hollow tube made of quartz glass or heat-resistant glass, and one end of the outer tube 1 is in contact with the base 7k of the atomizer 7 as described above and is airtightly closed. A spray port 73 of the atomizer 7 is opened at the center of the closed end 1a. An outlet nozzle 11 communicating with the vaporization gap 3, which will be described later, is provided on the outer peripheral surface of the outer tube 1 on the opposite side to the closed end 1a.

The inner tube 2 is a cylindrical hollow tube made of quartz glass or heat-resistant glass, which is thinner than the outer tube 1. Then, it is inserted and arranged inside the outer tube 1 concentrically with the outer tube 1. The tip head portion 2a on the insertion end side of the inner tube 2 is closed and is formed in a hemispherical shape. In the embodiment shown in the figure, the shape of the tip head 2a is hemispherical, but the shape is not limited to this, and may be a spheroidal surface, a rotating paraboloid, or a conical shape.

In the case of the figure, the outer tube 1 and the inner tube 2 are integrally connected to the entire circumference at the heater insertion side end of the outer tube 1. Of course, the inner tube 2 and the outer tube 1 may be separated from each other, but in that case, the heater insertion side opening portion of the outer tube 1 of the vaporization gap 3 formed between the inner tube 2 and the outer tube 1 is completely covered. The closing member (not shown) is closed over the circumference. The closing member is vaporized, and a material that is not affected by the flowing fluid Q flowing through the vaporization gap 3 is selected.

On the outer peripheral surface of the inner tube 2, at least three minute protrusions 2t are provided on the same circumference in two upper and lower stages in the drawing, and when the inner tube 2 is inserted into the outer tube 1, these minute protrusions are provided. 2t comes into contact with the inner peripheral surface of the outer tube 1 to form a uniform and sufficiently narrow vaporization gap 3 between the inner tube 2 and the outer tube 1 over the entire circumference. The vaporization gap 3 is connected to the outlet nozzle 11 on the heater insertion end side as described above. The outlet nozzle 11 is connected to, for example, a mass flow controller S that supplies the vaporized gas G2 to the reaction furnace H for oxidizing the silicon substrate by the mass flow rate. Since the outlet nozzle 11 is also a part of the outer tube 1, it is made of quartz glass or heat-resistant glass.

The width W of the vaporization gap 3 is not particularly limited, but the width W is preferably a range in which a temperature boundary layer having a high heat transfer coefficient is formed from the viewpoint of vaporization efficiency. That is, when the temperature of the flowing fluid Q flowing through the vaporization gap 3 is the wall surface temperature of the outer peripheral surface of the inner tube 2 or the inner peripheral surface of the outer tube 1, the fluid temperature gradually decreases as the distance from the wall surface increases. It becomes a constant temperature (uniform flow temperature) at a certain temperature. The range where the temperature becomes constant from the wall surface is the temperature boundary layer, and it is preferable that the width W of the vaporization gap 3 is within this range.

In the embodiment of FIG. 1, the opening ends of the inner tube 2 and the outer tube 1 on the heater insertion side are fused over the entire circumference as described above, and the opening end on the heater insertion side of the vaporization gap 3 is formed. It is blocked all around. The tip head 2a of the inner tube 2 housed in the outer tube 1 faces the spray port 73, and an atomization space M is formed between the closed end 1a provided with the spray port 73 and the tip head 2a. It is provided. Then, the vaporization gap 3 communicates with the atomized space M over the entire circumference.

The inner tube 2 is open on the heater insertion end side, and is concentrically inserted into the inner heater block 8 from here. A heater 9 is inserted in the center of the inner heater block 8, and a temperature sensor 12 such as a thermocouple is inserted in the vicinity thereof.
The inner heater block 8 is made of aluminum or solid graphite (graphite), and its outer surface shape is similar to that of the inner surface shape of the inner tube 2. Therefore, a very small gap is generated between the outer surface of the inner heater block 8 and the inner surface of the inner tube 2, and the graphite powder is filled in this gap to form the inner filling layer 10. The filled graphite powder of the inner packed layer 10 and the outer packed layer 6 described later is not only excellent in thermal conductivity but also excellent in lubricity because coarseness and density occur due to the filling condition and gravity as described later. It is also important that the shape is selected from scaly graphite, massive graphite, earthy graphite, artificial graphite, high-purity graphite, flaky graphite, spheroidal graphite and the like.

The graphite powder forming the inner packed layer 10 and the outer packed layer 6 is powdery or granular or a mixture thereof having a particle size range of 5 to 500 μm, and more preferably 10 to 100 μm.

Comparing the coefficient of thermal expansion of graphite (graphite) and aluminum, the coefficient of thermal expansion of graphite (graphite) is 2.6 × ^10-6 / K, and the coefficient of thermal expansion of aluminum (approximately value). Is 23 × 10 ^-6 / K, and graphite is about 1/9 smaller than aluminum.
Comparing the thermal conductivity of aluminum, graphite (graphite), stainless steel and the heat transfer paste used conventionally, aluminum is 210 W / m · K, graphite is 50 W / m · K, and stainless steel is 20 W / m · K. The heat transfer paste is 0.96 W / m · K, and graphite is inferior to aluminum but far superior to conventional heat transfer pastes.

The outer heater block 5 is a cylindrical member, made of aluminum or graphite, and concentrically houses the outer tube 1 inside. The inner diameter of the storage hole 5a of the outer heater block 5 is one size larger than the outer diameter of the outer tube 1, a gap is provided between them, and an outer filling layer 6 filled with graphite powder is provided. A plurality of outer heaters 4 are arranged at equal angles on concentric circles around the storage hole 5a.
Then, the outlet nozzle 11 provided on the side surface of the outer tube 1 is pulled out from the through hole 5h provided on the side surface of the outer heater block 5. When the outer heater block 5 is made of solid graphite, it is housed in a casing (not shown).

The inner heater 9 is equipped with a temperature sensor 12 to control the temperature of the inner heater 9. The outer heater 4 may be controlled so as to be interlocked with the temperature sensor 12 of the inner heater 9, or although not shown, the outer heater 4 may also be provided with its own temperature sensor.

Next, the operation of the vaporizer A of the present invention will be described.
FIG. 5 is an example of the apparatus configuration of the semiconductor manufacturing apparatus using the vaporizer A of the present invention, in which the liquid raw material L (hydrogen flow rate in this embodiment) is stored and the liquid raw material L is sent out by the pressurized gas G0. A fog that is connected to the raw material tank T, the raw material tank T, and is connected to a liquid flow rate controller E that sends out the supplied liquid raw material L by a constant flow rate, and an atomized gas supply source such as nitrogen gas or oxygen gas, and acts as these carriers. A mass flow rate controller S that sends out the chemical gas G1 by the mass flow rate, a liquid raw material introduction pipe 7b that receives the liquid raw material L sent out from the liquid flow rate controller E, and a spray gas that receives the atomized gas G1 from the mass flow rate controller S. An atomizer 7 including a tube 7a is provided at the inlet portion thereof, and for example, a vaporizer A that stably supplies a constant amount of vaporized gas G2 (water vapor containing hydrogen peroxide in this embodiment) to a reactor H for oxidizing a silicon substrate. It is composed of and.

In this device, when the inner heater 9 and the outer heater 4 are energized and the temperature rises, the inner heater block 8 and the outer heater block 5 accommodating them rise in temperature and start expanding. On the other hand, the outer tube 1 and the inner tube 2 do not thermally expand because the coefficient of thermal expansion is almost zero.

During heating, the diameter of the inner heater block 8 increases due to thermal expansion, and the gap between the inner peripheral surface of the inner tube 2 that does not expand and the outer peripheral surface of the inner heater block 8 becomes narrower by the amount of thermal expansion of the inner heater block 8. .. Since this gap is filled with graphite powder and this portion is the inner filling layer 10, the graphite powder subjected to the pressing force due to the thermal expansion of the inner heater block 8 flows due to its excellent lubricity. The degree of filling is optimized, the thermal expansion is absorbed, and a large pressing force is prevented from being applied to the inner tube 2 made of glass. This is shown in FIG. As a result, it is possible to prevent the glass inner tube 2 from being damaged during heating. As described above, the graphite powder has a coefficient of thermal expansion smaller than that of aluminum by about 1/9, which also contributes to the prevention of damage to the inner tube 2.

On the other hand, in the relationship between the outer heater block 5 and the outer tube 1, when the temperature of the outer heater block 5 rises, the inner diameter of the storage hole 5a of the outer heater block 5 that thermally expands with respect to the outer tube 1 that does not thermally expand increases. The gap forming the outer filling layer 6 between the inner peripheral surface of the storage hole 5a and the outer peripheral surface of the outer tube 1 increases. Therefore, the outer tube 1 is not damaged during heating on the outer heater block 5 side. However, the graphite powder filled in the gap (outer filling layer 6) moves downward due to gravity, albeit slightly, as the gap increases, and the outer filling layer 6 formed in the gap becomes coarse and dense. The relationship between the density and the outer tube 1 will be described in detail at the time of explaining the phenomenon during cooling.

Then, the heat of the outer heater 4 and the inner heater 9 is transferred to the outer tube 1 and the inner tube 2 through the outer heater block 5, the inner heater block 8, the outer filling layer 6 and the inner filling layer 10, respectively, but the outer filling Since the thermal conductivity of the graphite powder constituting the layer 6 and the inner filling layer 10 is 50 times or more higher than that of the conventional heat transfer paste, the outer tube 1 and the inner tube 2 are rapidly defined as compared with the conventional heat transfer paste. The temperature can be raised to the temperature in a short time. This means that in the case of using a conventional heat transfer paste having poor thermal conductivity, it was necessary to maintain the outer heater 4 and the inner heater 9 at a high temperature, but in the case of using graphite powder, heat transfer It can be achieved at a lower temperature than when using a paste.

When the outer tube 1 and the inner tube 2 are heated to a predetermined temperature, the liquid raw material L (hydrogen peroxide solution in this embodiment) is supplied to the atomizer 7 to the auxiliary supply hole 7d of the liquid raw material introduction pipe 7b, and at the same time, the spray gas pipe. The atomized gas G1 is press-fitted into the main supply hole 7c of 7a. As a result, the liquid raw material L becomes a mist-like fluid K from the spray port 73 and is blown into the atomization space M.

The mist-like fluid K collides with the spherical tip head 2a of the inner tube 2 and flows along the tip head 2a. At the outer peripheral edge of the tip head portion 2a, the flow flows in the tangential direction of the outer peripheral circle of the inner tube 2 or in a direction close to the tangential direction, and travels in the vaporization gap 3 toward the outlet nozzle 11 while swirling around the inner tube 2. That is, a swirling flow is generated in the vaporization gap 3. The flowing fluid Q that becomes this swirling flow and travels in the vaporization gap 3 initially contains a large amount of fine droplets in the vaporization gap 3, receives heat as it progresses, and gradually evaporates, and finally vaporizes. It becomes gas G2 and goes out. During this time, the flowing fluid Q becomes a swirling flow that swirls around the inner tube 2 and travels in the vaporization gap 3, so that a sufficient heating time can be secured. During this period, when the entire vaporization gap 3 is a temperature boundary layer, the swirling flow is heated to a temperature close to the wall surface temperature and rapidly vaporized, and is discharged from the outlet nozzle 11 to the mass flow controller S. Be supplied.

In this vaporization step, if an increase in the amount of vaporization of the liquid raw material L is required, it is necessary to supply the increased amount of heat to the outer tube 1 and the inner tube 2.
Since the conventional heat transfer paste has poor thermal conductivity, the temperatures of the outer heater 4 and the inner heater 9 must be raised, but graphite powder having excellent thermal conductivity is used as the outer filling layer 6 and the inner filling layer 10. By using it, the required amount of heat can be quickly supplied from the outer heater 4 and the inner heater 9, whereby the temperature of the outer heater 4 and the inner heater 9 can be suppressed to be lower than in the conventional case.

When the liquid raw material L is vaporized and supplied by a predetermined amount in this way, the energization of the outer heater 4 and the inner heater 9 is stopped and the vaporization work is completed. As a result, the outer heater block 5 and the inner heater block 8 are gradually cooled and contracted. On the other hand, the outer tube 1 and the inner tube 2 do not contract as described above, and the gap between them changes as described above.

That is, the diameter of the inner heater block 8 is reduced, and the gap forming the inner filling layer 10 between the inner peripheral surface of the inner tube 2 and the outer peripheral surface of the inner heater block 8 is widened by the contraction amount. Therefore, in the relationship between the inner heater block 8 and the inner tube 2, no pressure is applied to the inner tube 2 during cooling, and the inner tube 2 is not damaged by this. However, when the gap is widened by the amount of shrinkage, the graphite powder flows downward due to gravity, and the inner packing layer 10 is slightly coarse and dense. Damage to the inner tube 2 during the next heating due to this coarseness is avoided by the lubricity of the graphite powder described above.

On the other hand, in the relationship between the outer heater block 5 and the outer tube 1, when the outer heater block 5 is cooled, the inner diameter of the storage hole 5a of the outer heater block 5 decreases with respect to the outer tube 1 that does not shrink, and the storage hole 5a The gap forming the outer filling layer 6 between the inner peripheral surface of the outer tube 1 and the outer peripheral surface of the outer tube 1 is reduced. At this point, since the graphite powder forming the outer filling layer 6 between the two has coarseness due to gravity as described above, the portion densely filled by the shrinkage of the outer heater block 5 is started from the outer heater block 5. Tightening pressure is applied (dashed arrow on the right side of FIG. 3).

Since the graphite powder forming the outer filling layer 6 has excellent lubricity, when the tightening pressure is applied, the graphite powder in the portion flows and is pushed up due to its high lubricity, and the tightening pressure on the outer tube 1 is increased. Significantly suppress the rise. As a result, damage to the outer tube 1 during cooling is prevented.

When the atomizer 7, outer tube 1 and inner tube 2 of the vaporizer A are made of quartz glass, even if the liquid raw material L is hydrogen peroxide solution, it is not affected by the hydrogen peroxide solution, so that silicon is used. It can be applied to the surface oxidation of the substrate.

A: Vaporizer, E: Liquid flow rate controller, G0: Pressurized gas, G1: Atomized gas (carrier gas), G2: Vaporized gas (steam), H: Reactor, K: Atomized fluid, L: Liquid Raw material, M: Atomized space, Q: Flowing fluid, S: Mass flow controller, T: Raw material tank, W: Width of gap for vaporization, 1: Outer tube, 1a: Closed end, 2: Inner tube, 2a : Tip head, 2t: Protrusion 3: Vaporizing gap 4: Outer heater, 5: Outer heater block, 5a: Storage hole, 5h: Through hole, 6: Outer filling layer, 7: Atomizer, 7a: Spray gas Tube, 7b: Liquid raw material introduction tube, 7c: Main supply hole, 7d: Sub supply hole, 7k: Base, 8: Inner heater block, 9: Inner heater, 10: Inner filling layer, 11: Outlet nozzle, 12: Temperature Sensor, 73: Spray port

Claims (3)

An atomizer that atomizes and blows out liquid raw materials,
A hollow outer tube of the atomizer connected to the base on which the spray port is formed and made of quartz glass or heat resistant glass.
An inner tube housed in the outer tube and made of quartz glass or heat-resistant glass,
In a vaporizer provided inside the inner tube and including an inner heater block containing an inner heater.
The tip head on the insertion side of the inner tube is arranged so as to face the spray port direction, and an atomizing space is provided between the base portion on which the spray port is formed and the tip head on the insertion side. ,
A vaporization gap communicating with the atomized space is provided between the inner peripheral surface of the outer tube and the outer peripheral surface of the inner tube.
A vaporizer characterized in that an inner packing layer filled with graphite powder is formed between the inner peripheral surface of the inner tube and the outer peripheral surface of the inner heater block. An outer heater block provided on the outside of the outer tube and equipped with an outer heater is further provided.
The vaporizer according to claim 1, wherein an outer packing layer filled with graphite powder is formed between the outer peripheral surface of the outer tube and the inner peripheral surface of the outer heater block. The vaporizer according to claim 1 or 2, wherein the inner heater block 8 is formed of a graphite block.

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